 |
 |
 |
|
||
|
|||
|
|
2008 SURI Intern Year: Sophomore Research Project Transcranial magnetic stimulation (TMS) is a noninvasive method that stimulates neurons in the brain and helps to study circuitry in various areas. TMS is being used to study the primary motor cortex (M1) in humans because one of the major functions of the M1 in humans is to control voluntary movements. It is known that applying a TMS pulse to the motor cortex at the same time that a subject is performing a motor task can result in greater plasticity. This phenomenon can be useful in stroke patients if one area of the brain is damaged and non-functional, since another area may take over some of the functions. Prior to testing, subjects must first show in an inclusion experiment that they are capable of demonstrating measures of use-dependent plasticity. In this experiment TMS evokes thumb movements. The direction of the evoked thumb movements is termed baseline direction. Next, the subject is asked to execute thumb movement in a direction that is opposite to the baseline direction (extension/flexion and left/right) for a certain time period. During the performance of thumb movements, TMS is applied to the motor cortex involved in generating the training movements. TMS pulses are timed to stimulate motor cortex at a specific time in relation to the training movement. The important hand muscles being tested are the extensor pollicis brevis (EPB), a muscle that extend the thumb and flexor pollicis brevis (FPB), a muscle that is flexing the thumb. After the training movements, subjects are stimulated similar to the baseline condition to see how many TMS-induced thumb movements now appear in the trained direction (opposite to the baseline direction, a measure of use-dependent plasticity). During the summer I will help perform motor experiments on healthy subjects to examine the optimal TMS stimulation settings. Click here to review the summary report of this project. |
|
||||